ABSTRACT
The interaction energy of a methane molecule encapsulated in a dodecahedral water cage is calculated using the MP2, MP2C, various dispersion-corrected DFT, and diffusion Monte Carlo (DMC) methods. The MP2, MP2C, and DMC methods give binding energies of -5.04, -4.60, and -5.3 ± 0.5 kcal/mol, respectively. In addition, the two- and three-body contributions are evaluated using the DFT, MP2, and CCSD(T) methods. All of the DFT methods considered appreciably overestimate the magnitude of the three-body contribution to the interaction energy. The two- and three-body energies are further analyzed by use of symmetry-adapted perturbation theory (SAPT) which allows decomposition into electrostatics, exchange, induction, and dispersion contributions. The SAPT calculations reveal that the induction, dispersion, and exchange three-body contributions to the methane-cage binding energy are all sizable, with the net three-body contribution to the binding energy being about 1 kcal/mol.
ABSTRACT
A one-pot synthesis of substituted dihydrofurans was developed through a Lewis base-catalyzed three-component cascade condensation between nitroalkenes, aldehydes, and 1,3-dicarbonyl compounds. The desired cyclization products were prepared with a large substrate scope (22 examples) and excellent diastereoselectivity (only trans isomers) in good to excellent yields (up to 95%).